Illumination devices, such as fiber optics, have many applications and generally employ conventional methods such as reflective surfaces or total internal reflection to deflect or focus the light energy. Some devices also have modifications of the distal end or tip geometry to generate focused or defocused beams. Tip modifications for optical fibers are typically produced by polishing or grinding of the fiber tip or the end of a bundle of fibers. Conventional techniques have also included use of high temperatures such as with use of a fusion splicer to create ball tip structures generated by melting the core of an optical fiber.
The limitation of these techniques is that they require accurate manipulation of the device resulting in a modified section which is then left unprotected. For optical fibers, the techniques for polishing or manipulating the tip are costly, time consuming and result in a fragile end product. The techniques available for creating lensing surfaces using the device itself are limited and generate limited optical output lensing options.
Illumination devices such as laser fibers for medical use are frequently used either in direct contact with tissue or in a fluid medium. In these settings, focus of the laser beam emanating from the fiber is difficult to control due to the similar indices of refraction of the various media and the fiber.
What is needed is a versatile technique for terminating illumination devices, or for adapting illumination devices to optimize the light energy and provide desired optical performance.